A little electricity 101 if you please

[Doug Miller]

Care to explain how that's going to happen with the breaker off?

[HeyBub]

Generally true. But you COULD have flipped the wrong breaker (or there's some unknown mis-wiring) AND be, yourself, a path to ground (neutral).

True.

That'll work - unless someone calls at the instant you've got the wires in your mouth. The ring voltage is north of 50 volts.

[RBM]

Probably every manufacturer made them, but the ones I've seen most often are Federal Pacific, from NJ

[RBM]

I'm not saying that your panel, or any panel has to have a "main". I'm saying your service and every service has to have at least one main disconnect. It may not be in your panel. It may be part of the meter equipment, it may be on a pole, but somewhere, there is a means to kill the power to each service

[Larry]

Isn't that more correctly worded as "no more than 6" ?

[Eigenvector]

Ahhh, now I understand you. Thanks. I'm glad I persisted in asking.

[Eigenvector]

Well not answering for him, but I was asking about this in the off-chance that the breaker might not have been off. I was more interested in whether or not a shock is possible when all you're touching is two hot wires - obviously when the breaker's off you shouldn't get shocked (but that's why you measure it with a meter first) at any time. I realize that this is one of those questions where I'm treading on dangerous ground and the responses need to be stated carefully so as not to mislead someone reading it who may not have been following the whole conversation.

[Eigenvector]

Obviously I'm not gonna be stripping phone line with my teeth, there are better tools for that. But by using that case it is easier to make a point about what's in a phone line.

[Doug Miller]

Of course it is. A shock is possible when you're touching *one* hot wire. And it's also possible when touching the *neutral* wire, if the circuit is energized.

Right, and that's also why you test the meter first, by measuring something that's known to be live.

If the right breaker is off, and everything has been wired correctly, you can't get shocked.

[RBM]

That wording may imply that none are required

[Doug Miller]

OK, how about "at least one, but not more than six" ?

[RBM]

It's all coming clear to me now

[Tom J]

Mine is a Federal Pacific also, but the panel next door is the same form and it's a Square D and the replacement circuit breaker panel I'm installing next week that has the same form is a Square D. So it's not MADE them, because they are still being made.

Tom J

RBM wrote:

[RBM]

I said "made" because not all manufacturers are still making them, least of all Federal Pacific

[Nexus7]

True. It was the practice to have shared neutral circuits, you get two circuits out of 3 wires. The 2 hots were supposed to be hooked up to different busbars, so that the currents in the neutral were out of phase, but over the years, they end up sometimes on the same side. If I can't run an extra wire, I'll hook the two up to a ganged breaker, so that they're on opposite busbars, and on breaker turns both off.

It is relevant here, because when they're on different breakers, throwing one breaker doesn't mean that the neutral isn't hot.

[Brian O]

But in the case we are refering to, the "MAIN" kills everything in the panel that runs into the house. Including the 220 v circuits that run into the house. The only thing that is still hot in the panel is the buss bars above the "main" and the wires feeding them (usually from the electric company service cables). If the "main" is thrown, all the circuits in the house should be dead unless they are wired incorrectly or have some circuits fed from another panel connected to the electric co mains (which probably is not allowed by NEC). I was an electrician back in the 80s for about 7 yrs and never ran across a resedintial panel that had more than one "main" breaker, and I saw a lot of them. Brian

[Doug Miller]

No, it absolutely is *not* true that "neutrals ... are usually shared by two circuits."

Normal installation is for each circuit to have its own neutral.

[Brian O]

[Mark Lloyd]

The house my grandparents used to live in was built for few if any

240V loads. Several were added later (stove, dryer, window air conditioners, 2 electric kilns). Each one added a disconnect box on the wall next to the meter. It looked more like 10 of them than 5.

I can't check since that house has since been rewired.

[Nexus7]

Can you define "normal" installation?

The posting followed up to advised the OP that he should watch out for shared-neutral circuits. That is a valid concern, regardless of what you think "normal" installation is.